Swinger is one moaning, naked (5)
I believe the answer is:
hinge
'swinger' is the definition.
(I've seen this in another clue)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for hinge that I've seen before include "Joint on which something turns" , "Circumstance upon which subsequent events depend; door facilitator" , "Pivotal point" , "Device for letting door etc swing" , "Moveable joint" .)